Suwadee Kongparakul

Green biodiesel production from waste cooking oil using an environmentally benign acid catalyst.

The application of an environmentally benign sulfonated carbon microsphere catalyst for biodiesel production from waste cooking oil was investigated. This catalyst was prepared by the sequential hydrothermal carbonization and sulfonation of xylose. The morphology, surface area, and acid properties were analyzed. The surface area and acidity of the catalyst were 86m(2)/g and 1.38mmol/g, respectively. In addition, the presence of sulfonic acid on the carbon surface was confirmed by Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy. The catalytic activity was tested for biodiesel production from waste cooking oil via a two-step reaction to overcome reaction equilibrium. The highest biodiesel yield (89.6%) was obtained at a reaction temperature of 110°C, duration time of 4h, and catalyst loading of 10wt% under elevated pressure 2.3bar and 1.4bar for first and second step, respectively. The reusability of the catalyst was investigated and showed that the biodiesel yield decreased by 9% with each cycle; however, this catalyst is still of interest because it is an example of green chemistry, is nontoxic, and makes use of xylose waste.

Preparing hydrophobic nanocellulose-silica film by a facile one-pot method

Hydrophobic nanocellulose-silica film was successfully prepared by a facile one-pot method using tetraethoxysilane (TEOS) and dodecyl triethoxylsilane (DTES). Morphological characterization of the hydrophobic nanocellulose-silica (NC-SiO2-DTES) film showed well self-assembled DTES modified silica spherical nanoparticles with the particle sizes in the range of 88-126nm over the nanocellulose film. The hydrophobicity of the NC-SiO2-DTES film was achieved owing to the improvement of roughness of the nanocellulose film by coating dodecyl- terminated silica nanoparticles. An increase in DTES loading amount and reaction time increased the hydrophobicity of the film, and the optimum condition for NC-SiO2-DTES film preparation was achieved at DTES/TEOS molar ratio of 2.0 for 8h reaction time. Besides, the NC-SiO2-DTES film performed superoleophilic property with octane and hexadecane contact angles of 0°. It also showed an excellent hydrophobic property over all pH values ranged from 1 to 14.

Green Process for Natural Rubber Latex Hydrogenation via Metathesis

Natural rubber (NR) is an important renewable polymeric material which contains cis-1,4-polyisoprene as a major component. A new approach for a green hydrogenation process has been developed in this research work. This metathesis/hydrogenation method has less detrimental environmental impact and provides improved thermal stability of NR.

Selective production of aromatic hydrocarbons from catalytic pyrolysis of biomass over Cu or Fe loaded mesoporous rod-like alumina

The selective production of aromatic hydrocarbons from bio-oil derived from the fast pyrolysis of sunflower stalks over Cu or Fe-modified mesoporous rod-like alumina catalysts was investigated. Uniform mesoporous rod-like alumina with different pore sizes were successfully synthesized using a hydrothermal method with the assistance of Pluronic P123 surfactant. A high relative total hydrocarbon amount of about 59% in the upgraded bio-oil was obtained when pure mesoporous Al2O3 with a uniform pore size of 5.81 nm was used. Mesoporous Al2O3 with a larger pore size resulted in more polycyclic aromatic hydrocarbons (PAHs) such as indenes and naphthalenes being generated. Cu or Fe loaded Al2O3 with a loading amount in the range of 1–2.5 wt% showed a high selectivity towards monocyclic aromatic hydrocarbons (MAHs) such as benzene, toluene and xylenes (BTXs) over 80%. By using 2.5 wt% Cu/Al2O3-0.01, the highest relative total hydrocarbon amount reached 89%, which consisted of about 84% aromatic hydrocarbons and 4.9% aliphatic hydrocarbons. Both catalysts showed good catalytic stability and regeneration properties. A catalytic system with high effectiveness and long-term stability was expected to be obtained to convert the oxygenated compounds in bio-oil to high value-added hydrocarbons.

Fabrication and evaluation of nanocellulose sponge for oil/water separation

Nanocellulose sponge was fabricated by a facile method: freeze-drying of nanocellulose aqueous suspension to sponge state, following by hydrophobic treatment with stearoyl chloride at 50 °C for 1 h. The obtained nanocellulose sponge showed superhydrophobicity (160° of water contact angle) and superoleophilicity with high protection from water but selective absorption of oil. Its absorption capacities for various kinds of oil and non-polar liquids were 25-55 times higher than its dry weight and exhibited excellent selectivity for absorbing of oil which spilled on the surface of water or underwater with high separation efficiency. This superhydrophobic nanocellulose sponge can be easily recovered by simple squeezing and reused at least 10 cycles with remained high separation efficiency. It is expected that such a biodegradable nanocellulose sponge can be applied to solve the oil spill accident and treat the oily wastewater from households and industries.

Grafted Methyl Methacrylate and Butyl Methacrylate onto Natural Rubber Foam for Oil Sorbent

NR foam was modified via graft copolymerization with oleophilic monomer such as methyl methacrylate (MMA) or butyl methacrylate (BMA). Polymethyl methacrylate (PMMA) and polybutyl methacrylate (PBMA) were prepared by emulsion polymerization. The average particle size of PMMA and PBMA emulsion were 58.7±5.3 nm and 57.6±0.8 nm, respectively. The effect of PMMA or PBMA emulsion loading onto NR foam was studied over the range 0.05 2.0 phr. The functionality of modified NR foam was characterized by Fourier Transform Infrared Spectroscopy (FTIR). Thermal properties of modified NR foam were confirmed by thermogravimetric analysis (TGA). The results showed two step degradations which were attributed to natural rubber and PMMA or PBMA contents. The modified NR foam could quickly absorb gasoline and organic solvent such as toluene and xylene, which found in petroleum product. The maximum oil absorbency (gram of absorbency per gram of foam) of gasoline, diesel, engine oil, toluene and xylene were achieved at 9.95, 8.37, 6.01, 11.81 and 10.96, respectively. Modified NR foam had high oil absorption capacity, reusability, easy to use and good environmental friendly. It can be used as an alternative sorbent material for oil spill cleanup.

Efficient Conversion of Renewable Unsaturated Fatty Acid Methyl Esters by Cross-Metathesis with Eugenol

Cross-metathesis of unsaturated fatty acid methyl esters (methyl oleate (MO), methyl petroselinate (MP), and methyl erucate (ME), obtained from vegetable oils) with eugenol (obtained from clove oil) proceeded under green, mild conditions (in 2-propanol or ethanol at 50 °C) in the presence of a ruthenium-carbene catalyst (called a second-generation Grubbs catalyst). These metathesis reactions proceeded with both high conversion (>90% of MO, MP) and selectivity (>98%) even with low catalyst loading (0.1 mol % Ru).